碳掺杂耦合氧化铈共修饰氮化碳光催化处理焦化尾水

doi:10.19965/j.cnki.iwt.2024-0631

摘要/Abstract

摘要：

强化焦化废水深度处理对于实现焦化废水零排放至关重要。流程短、成本低、效率高的光催化技术已在水中有机物去除方面展现出应用潜力。在众多光催化剂中，基于石墨相氮化碳（g-C₃N₄，GCN）所开发的新型光催化剂备受青睐。利用一步水热与煅烧法合成了负载CeO₂的C自掺杂氮化碳（CeO₂/GCNC），并用其处理焦化尾水。CeO₂/GCNC2展现了良好的光催化去除焦化尾水中COD的性能，120 min内对焦化尾水中COD的去除率达到了56.79%，相对于氮化碳单体提高了5.3倍。其中，CeO₂/GCNC2优越的光催化性能得益于C自掺杂拓宽了材料的光利用范围和负载的CeO₂在光催化过程中作为助催化剂，不仅可以聚集光激发电子，其独特的Ce⁴⁺/Ce³⁺氧化还原对的存在可作为电荷迁移介质来促进光生电子的迁移，从而提高了光生电子空穴对的分离效率。

关键词: 氧化铈, 碳自掺杂, 氮化碳, 焦化废水, 光催化

Abstract:

In this study,carbon self-doped g-C₃N₄ loaded with CeO₂ photocatalyst(CeO₂/GCNC) was synthesized via a facile one-pot hydrothermal and calcination method. The CeO₂/GCNC exhibited superior photocatalytic treatment for coking wastewater, and the removal rate of COD in coking wastewater reached 56.79% within 120 min, which was 5.3 times higher than that of pure g-C₃N₄. The superior photocatalytic performance of CeO₂/GCNC2 can be attributed to the C self-doping that broadens the light utilization range of the material and the loaded CeO₂ acting as a cocatalyst during the photocatalytic process, which not only aggregated photoexcited electrons, but also worked as a charge mobility mediator for the migration of photogenerated electrons by the presence of its unique Ce⁴⁺/Ce³⁺ redox pairs, thus improved the separation efficiency of photogenerated electron-hole pairs.

Key words: cerium oxide, C self-doping, graphite carbon nitride, coking wastewater, photocatalytic

中图分类号:

X703.1

安宁, 胡绍伟, 王飞, 刘芳, 陈鹏, 王永, 李函霏, 孙中琦. 碳掺杂耦合氧化铈共修饰氮化碳光催化处理焦化尾水[J]. 工业水处理, 2025, 45(8): 167-173.

Ning AN, Shaowei HU, Fei WANG, Fang LIU, Peng CHEN, Yong WANG, Hanfei LI, Zhongqi SUN. Carbon self-doping coupled with cerium oxide co-modified graphite carbon nitride for photocatalytic treatment of coking wastewater[J]. Industrial Water Treatment, 2025, 45(8): 167-173.

https://www.iwt.cn/CN/Y2025/V45/I8/167

图/表 13

图1 CeO₂、GCN、GCNC、CeO₂/GCNC的XRD

Fig. 1 XRD spectra of CeO₂，GCN，GCNC and CeO₂/GCNC

图2 GCNC、CeO₂/GCNC2的FE-SEM（a、b）及CeO₂/GCNC2的TEM、HRTEM、EDS元素映射图（c、d、e）

Fig.2 FE-SEM image of GCN（a，b） and TEM image，HRTEM image，corresponding EDS elemental mapping image of CeO₂/GCNC2（c，d，e）

图3 GCN、GCNC、CeO₂/GCNC2的XPS

Fig. 3 XPS spectra of the GCN， GCNC， CeO₂/GCNC2

表1 所制材料元素的原子数分数

Table 1 The atomic fraction of elements in the as-prepared material

催化剂	原子数分数/%
催化剂	C	N	O	Ce
GCN	38.41	58.44	3.15	0
NGCN	42.88	53.33	3.79	0
CeO₂/NGCN2	39.56	51.18	5.03	4.23

图4 GCN、GCNC、CeO₂/GCNC2的UV-vis DRS图（a）和带隙能图谱（b）

Fig. 4 UV-vis diffuse reflectance spectra，bandgap energy of GCN，GCNC and CeO₂/GCNC2

图5 GCN、GCNC、CeO₂的肖特基测试图

Fig.5 Mott-Schottky plots of GCN，GCNC and CeO₂

图6 GCN、GCNC、CeO₂/GCNC2的瞬态光电流密度图（a）、EIS阻抗谱图（b）

Fig.6 Photocurrent responses（a），EIS Nyquist plots（b） of GCN，GCNC and CeO₂/GCNC2

图7 GCN、GCNC、CeO₂/GCNC2的N₂吸附-脱附等温曲线

Fig.7 The nitrogen adsorption-desorption isotherms of GCN，GCNC and CeO₂/GCNC2

表2 GCN、GCNC与CeO₂/GCNC2的比表面积与孔容

Table 2 The BET surface area and pore volume of GCN，GCNC and CeO₂/GCNC2

样品	GCN	GCNC	CeO₂/GCNC2
比表面积/（m²·g^-1）	13.022	13.566	32.947
孔容/（cm³·g^-1）	0.065	0.081	0.141

图8 GCN、GCNC、CeO₂/GCNC的降解效果

Fig.8 Photodegradation curves of GCN，GCNC and CeO₂/GCNC

图9 循环实验

Fig.9 Cyclic experiment

图10 CeO₂/GCNC2的自由基捕获实验结果

Fig.10 The free radical trapping experimental results for degradation of COD over CeO₂/GCNC2

图11 CeO₂/GCNC2的光催化机理

Fig.11 The possible photocatalytic mechanism of CeO₂/GCNC2

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